#include <stdio.h>

extern int add(int num1, int num2);
extern int sub(int num1, int num2);
extern int div(int num1, int num2);
extern int mul(int num1, int num2);



int main()
{
    int a = 20, b = 2;
    printf("add(a,b) = %d\n", add(a,b));
    printf("sub(a,b) = %d\n", sub(a,b));
    printf("div(a,b) = %d\n", div(a,b));
    printf("mul(a,b) = %d\n", mul(a,b));

    return 0;
}